Horsetail

Scientific Name(s): Equisetum arvense L., Equisetum myriochaetum
Common Name(s): Bottle brush, Dutch rushes, Horse willow, Mexican giant horsetail, Paddock-pipes, Pewterwort, Scouring rush, Shave grass, Toadpipe

Medically reviewed by Drugs.com. Last updated on Aug 23, 2021.

Clinical Overview

Use

Horsetail has traditionally been used as a diuretic, as an astringent to stop bleeding and stimulate healing of wounds and burns, and as a cosmetic component, as well as for treatment of tuberculosis and of kidney and bladder ailments (eg, urethritis, cystitis with hematuria); however, clinical trials are lacking to support these uses. Clinical data demonstrate a hypoglycemic effect with use of E. myriochaetum and efficacy in treating brittle nails with use of E. arvense.

Dosing

Equisetum palustre products are contraindicated for use in humans. Brittle nails: A formulation containing E. arvense applied topically every night for 28 days or every other day for 14 days has been used to strengthen fingernails in clinical trials. Diuretic: A dry extract of the aerial parts of E. arvense containing 0.026% total flavonoids has been administered as 300 mg orally 3 times daily. Type 2 diabetes: A water extract of a related species of horsetail (E. myriochaetum) as a single oral dose of 0.33 g/kg has been used in a clinical study. Wound healing: An E. arvense 3% ointment applied topically every 12 hours for 10 days has been used following episiotomy in postpartum mothers.

Contraindications

Horsetail has been listed as an herb of undefined safety by the US Food and Drug Administration (FDA). Horsetail remedies prepared from E. arvense are generally considered safe when used properly. However, another species of horsetail, E. palustre, is poisonous to horses; contraindicated for use in humans.

Pregnancy/Lactation

Avoid use. Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented.

Adverse Reactions

Documented adverse effects possibly associated with horsetail include acute pancreatitis and an isolated incident of headache.

Toxicology

Horsetail has been listed as an herb of undefined safety by the FDA. Horsetail remedies prepared from E. arvense are generally considered safe when used properly. However, another species of horsetail, E. palustre, is poisonous to horses; contraindicated for use in humans. E. arvense may be toxic, especially in cases of underlying liver disease. There have been reports of children being poisoned by using the stems as blowguns or whistles.

Scientific Family

• Equisetaceae

Botany

E. arvense is native to Europe, North America, North Africa, and Northern AsiaChevalier 1996 and grows best in moist and shady areas.Weiss 1992 Horsetail is a pteridophyte more closely related to ferns than to flowering plants; it produces spore sacs that are visible from March through September.Hallowell 1994 The plant is a small, deep-rooted, rush-like perennial that grows about 0.3 m in height. It has hollow, pointed stems, scale-like leaves, and no flowers. Mexican giant horsetail (E. myriochaetum) is a species of horsetail native to regions of South America.Revilla 2002

History

The word "Equisetum" is derived from the Latin "equus," meaning "horse," and "seta," meaning "bristle."UMMC 2017 The plant has traditionally been used as a diuretic, and in the treatment of tuberculosis, GU and respiratory disorders, arthritis, and bleeding ulcers.Lininger 1998 Because of i...